Gets or sets the constant opacity value to be used in painting the annotation. This value applies to all visible elements of the annotation in its closed state (including its background and border) but not to the popup window that appears when the annotation is opened.

public double Opacity { get; set; }

Public Property Opacity As Double
	Get
	Set

public:
property double Opacity {
	double get ();
	void set (double value);
}